1. Field of the Invention
The present invention relates to a method and apparatus for simplifying a signal coded and modulated by the ETS (European Telecommunication Standard)--HIPERLAN (High Performance Radio Local Area Network).
2. Description of the Prior Art
The so-called European Telecommunications Standard (ETS) defines the technical characteristics of a wireless local high performance network (High Performance Radio Local Area Network=HIPERLAN). HIPERLAN is a short-range communications subsystem with a high data rate (compare ETSI 1995, ETS 300 652, UDC: 621 396).
The ETS-HIPERLAN standard is intended for USC in the 5.15 to 5.30 GHz frequency band.
The HIPERLAN standard exactly defines the mapping of data onto the transmitted signal which is effected by coding and modulation. A receiver for a signal structured in this way can accomplish inverse mapping by sequentially cancelling the operations undertaken in the transmitter for generating the transmitted signal. For a receiver which is based on coherent demodulation this is not a problem for the most part in a transmitted signal formed according to the HIPERLAN standard.
Noncoherent demodulators are somewhat less complex than coherent demodulators and would be advantageous for HIPERLAN. But it happens that the step-by-step cancellation of the encoder and modulation stages in noncoherent reception leads to behaviours causing fatal error.